Multimedia cards are extensively known as one type of external storage media for use in personal computers, multifunctional terminal unit and the like. A multimedia card can be used for recording any kind of digital information such as in recording still pictures in a digital video camera, recording data in a mobile telephone or in recording music in a portable phonogram player.
The compatibility of these multimedia cards is maintained in accordance with multimedia card standards prescribed by the Multimedia Card Association (MMCA), which is an organization for standardization.
One of the detailed descriptions (in Japanese) of such IC cards is found in Masashi Oshima, ed., Denshi Zairyo (Electronic Materials), Kogyo Chosakai Publishing Co., Ltd., Dec. 1, 1990, pp. 22-26, which also describes technological trends regarding different kinds of IC cards.
However, the present inventors have found that a memory card of the type described above involves the following problems.
A multimedia card is a young product item having come into being along with the expanding use of the Internet and of mobile telephones, and there are frequent revisions in or additions to the multimedia card standards.
When the multimedia card standards undergo a revision or an addition, both the hardware and the firmware have to be modified accordingly, forcing the users to bear the load of a high cost and a long time.
On the host side as well, there many items of equipment which do not satisfy the multimedia card standards, and this also necessitates revision of the hardware and firmware of the multimedia card.
An object of the present invention is to provide a memory card and a data rewriting method therefore making possible adaptation to any revision in or addition to the standards at low cost and in a short period of time by merely altering the firmware.
The above-described and other objects and novel features of the invention will become more apparent from the following description in this specification when taken in conjunction with the accompanying drawings.